1. Field of the Invention
The invention relates to large current terminals and methods of metal-working such terminals. More particularly, the invention is directed to large current terminals applied to connectors used for wire harnesses of electric cars, their structure, and methods of making such terminals
2. Related Art
Since connectors used as wire harnesses for electric cars must have a large current-carrying capacity, terminals thereof, both male terminals and female terminals, must also have a structure suitable for high ampacity.
To achieve high ampacity and low contact resistance, terminals of a connector have been formed by cutting a solid conductive rod having a round cross-section.
The structure of such a male terminal for the connector (hereinafter referred to simply as "the male terminal") and a female terminal for the connector (hereinafter referred to simply as "the female terminal") as well as methods of forming such terminals will hereunder be described with reference to the accompanying drawings, which are FIGS. 16 to 19.
FIG. 16 is a side view of a female terminal made by a cutting process and FIG. 17 is a sectional view taken along a line X--X of FIG. 16. In FIGS. 16 and 17, a female terminal 51 is formed by cutting the outer circumference and inside of a solid round rod 52 with a cutting tool. A wire crimping part 53 and an electric contact part 54 are also formed by the same cutting process. In addition, an engaging hole 55 for allowing a cylindrical contact spring member to be inserted and engaged with the inner circumferential wall of the female terminal is also bored similarly with the cutting tool.
Then, FIG. 18 is a side view of a male terminal made by a cutting process; and FIG. 19 is a sectional view taken along a line Y--Y of FIG. 18. In FIGS. 18 and 19, a male terminal 61 is similarly formed by cutting the outer circumference and inside of a solid round rod 62 with a cutting tool. A wire crimping part 63, an electric contact part 64, and a collar 65 are respectively formed by the same cutting process. In addition, a hollow space 67 for engaging a caplike contact with the inner wall of the nose of the electric contact part 64 is also bored similarly with a cutting tool.
However, to implement accurate metal working of the terminals based on the aforementioned art, it takes time since the main part of such work is the cutting process. Moreover, although it is possible to automate the major part of the cutting process, the finishing work must depend on the skill of an operator, from which arises inconsistency in product quality As a result, the problem of inconsistent finishes of the products have been imposed.
Furthermore, the problem of high cost has also been encountered.